Found some free hp on my blown big block!
 

Sci 575 in a velocity 280, boat runs hard, engine runs great. Low 90's with full tank and 2 people. I recently got a scan tool so I could watch live data and do tuning. Noticed at wot scanner was only reading 26 total timing, tune is set up for 32 under boost. Found a code 42, timing control issue. Did some diagnostic And verification with timing light agreed on the 26 timing. Replaced ignition module and ran a ground wire to distributor housing and now I show 35 degrees at 3500 no boost where before I had 26. The bump from 26 to 32 timing on a blown big block is probably 75 hp easy!!!

Nice find!

its also how those of us that have been at this game a while get paper weights for the counter or desk a beautiful bigblock piston with a hole in it!

6* of timing 75 horses thats a stretch..........:lolhit:

my na 565 i built went from 860hp with 30 degree to 915 at 7100 with 37 degrees .

Tell me more about that build.

11.2 comp 565, merlin block. Zero deck, afr 315, ported by Chris straub. Dart oval port intake ported to the rec heads. 1150 dominator. Mike Jones solid roller, 740 731, 258 265@50 114 lobe. Engine had a ton of mid hp and torque and carried the hp really good past peak for such a small head and cam. The intake really carries good air speed. Callies crank and rods je piston. 2.8 rod clearance, 3.0 main clearance, 3.5 clearance on rear main cap.

So back out on boat with timing fixed, picked up a solid 3.5 mph. Same prop, 15 degree warmer air temp. I'd say honest 60hp gain. Went from running average of 92 93 to 96 97. Zero knock on the scanner data. Adding the whipple intercooler should be good for another good gain in power. Probably can add 2 degrees of timing. I run 50 50 mix of av gas and 92 non ethonal.